This volume offers a cross-section of a good fifteen years of research in the sociology of technology and innovation at the Department of Sociology of Technology headed by Werner Rammert at the TU Berlin. All contributions in this volume were initiated or discussed there and thus bear in a certain sense a "Berlin signature" - not in the sense of a clearly delimited scientific school, but rather in the form of an open discussion group with different, but mutually related focal points. The Berlin Key, which gives it its title, imposes on all its users the program of action objectified in its mechanism: "User, if you want to take the key back to yourself after unlocking the door and go your way, you must lock the door again first. Unlike that Berlin key, the "Berlin Keys to the Sociology of Technology" presented here offer a set of keys to different but interconnected conceptual and methodological approaches in social science research on technology and innovation.